"To find that training on a working-memory task could result in an
increase in fluid intelligence would be cognitive psychology’s
equivalent of discovering particles traveling faster than light. ... 'Do
we think they’re now smarter for the rest of their lives by just four
weeks of training?” she asks. 'We probably don’t think so. We think of
it like physical training: if you go running for a month, you increase
your fitness. But does it stay like that for the rest of your life?
Probably not.' ... Just like physical exercise, cognitive exercises may
prove to be up against something even more resistant to training than
fluid intelligence: human nature." excerpts from Can You Make Yourself Smarter? by Dan Hurley